1. Field of the invention
The present invention relates to a method and a device for general and localized sanitizing of air and similar gas mixtures, particularly but not exclusively to be applied in aeraulic and climate-control systems of hospitals, business centers, offices and rooms in general, in the preparation and preservation of perishables, and for neutralizing or converting toxic gaseous compounds such as benzene, NOx and the like into non-toxic gaseous compounds.
2. Description of the Prior Art
Most modern buildings are equipped with sophisticated systems which maintain appropriate comfortable environmental conditions inside the buildings. In this context, the characteristics closely linked to the chemical composition of air, such as low bacterial activity, absence of pollution, et cetera, have become very important over the last decade because it has been found experimentally that conventional systems often cause the onset of certain diseases. Unless scrupulous maintenance of the system, consisting in effectively cleaning and disinfecting the surfaces that are in direct contact with the air, is performed at regular intervals, the system and particularly its ducts, filters et cetera become the ideal medium for the proliferation of viruses, molds and bacterial colonies such as the feared Legionella pneumophila and Bacillus cereus. On the other hand, the maintenance of installed systems is a very significant burden, since it mainly depends on the extent of the network of ducts, which can be very large in multistory buildings such as hospitals, shopping centers, et cetera. The adoption of electrostatic precipitation filters partially solves the problem of eliminating bacterial colonies by trapping dust, since it is well-known that many bacteria are conveyed in free air by dust, preferably on particles having a diameter of a few microns. It is also known that the organic decay of food products and the like is a natural and inevitable phenomenon triggered by bacteria and microbes conveyed everywhere by air and present in the air. This process of decay begins on the exposed surface that is in direct contact with the surrounding environment and then progresses inward until the component organic substances are completely deteriorated. The macroscopic effects of this phenomenon consist of the appearance of surface mold and a change in the odor and color of the food product. The main microscopic effects consist of the gradual loss of the organoleptic properties of the food product, which accordingly entails the decay of the nutritional properties thereof and their consequent toxicity. It is also known that the bacteria and microbes that are present in the air are active in every step of the production process of food for human beings and animals. At present, technology essentially offers an xe2x80x9cexternalxe2x80x9d method of intervention and an xe2x80x9cinternalxe2x80x9d method for delaying this process of decay. The xe2x80x9cexternalxe2x80x9d method consists of preservation at temperatures below 0xc2x0 C. until freezing is achieved, which physically paralyzes the noxious action of bacteria and microbes. The xe2x80x9cinternalxe2x80x9d method consists in adding substances, known as preservatives, which chemically inhibit this action. Very often, these methods are combined appropriately so as to further extend their effects. The main drawback of the xe2x80x9cexternalxe2x80x9d method is the high energy expenditure required to achieve prolonged preservation at such temperatures. In turn, the main drawback of the xe2x80x9cinternalxe2x80x9d method is the fact that the preservatives may, in the long term, turn out to be noxious for the human body. Experimental research has shown that ionized air has a strong bactericidal effect. For example, the researchers Philips, Harris and Jones, by nebulizing a large quantity of bacteria in an enclosed space and subjecting them to ionization, have found that the mortality rate of the bacterial load is 54% with positively ionized air and 78% with negatively ionized air. A further confirmation of this phenomenon is provided by the experience of the researcher Lautie, who ionized the air in an enclosed space with a volume of 120 m3 and with an approximate concentration of 83,000 bacteria per cubic meter of air, noting that this concentration dropped rapidly and became zero in approximately three quarters of an hour. Further confirmation is provided by the researchers Kellog and Fratini, who carried out tests and measurements on Staphilococcus aureus and on molds, respectively. These experimental findings are explained by the fact that ionization of the air leads to the breakdown of the bonds of oxygen molecules such as O2 and therefore produces free oxygen Oxe2x88x92, which in the gaseous state, being an oxidizing agent, has a bactericidal and microbicidal action.
The aim of the present invention is to overcome the drawbacks noted above, providing a method and a device for the general and localized sanitizing of air and similar gas mixtures which give the treated air high-level characteristics of purity both in terms of particulate and in bacteriological and microbial terms.
An object of the invention is to provide a method and a device which allow to prevent and eliminate the forming of molds and bacterial colonies along air distribution ducts and to effectively prolong the preservation of perishable products.
Another object of the invention is to provide a method and a device which allow a substantial reduction of maintenance interventions over time and specifically of interventions for cleaning along the ducts, extending their life, and to achieve this prolonged preservation, even in combination with known methods, at lower costs and in a more natural manner without producing ozone.
Another object of the invention is to provide a device which is preferably constituted by connectable modular units, so as to contain production costs, installation costs, maintenance costs and component replacement costs, and which is applied in many different fields in the sector of perishable product preparation and preservation.
This aim, these objects and others which will become apparent hereinafter are achieved by a method for the general and localized sanitizing of air and similar gas mixtures, as claimed in the accompanying claims.